1. Field of the Invention
The invention relates to a cat and mouse type rotary engine, as well as a similarly configured cat and mouse type fluid compressor/blower.
2. Description of the Related Art
Cat and mouse type rotary engines have used two irregularly shaped gears outside of the housing. Rotorheads are powered by the ignition of a fuel/air mixture, then two rotors convey the power to the two separate external gears, and those gears mesh respectively with two additional gears. The displacement of the meshing point of either set of two gears is either longer or shorter than that of the other set. This difference in displacement distance between the two sets results in a corresponding difference in the moments of force. Through such a mechanism, the power is converted to a rotational motion, i.e., an output shaft rotates in a direction determined by the larger of the moments of force.
This underlies a problem inherent in the prior art. There is a point in operation of the conventional cat and mouse device where the larger moment of force becomes smaller than the competing moment of force. Despite the values of the competing forces, the rotors continue to move in a direction of the smaller force because of the inertia of the rotors. Therefore, the prior cat and mouse type rotary engine was impractical for widespread use, due to a severe damage and heavy abrasion of gears caused by these features.
There is one cat and mouse type rotary engine design that overcomes such defect, such design being described in U.S. Pat. No. 5,224,847, whose inventorship is the same as that of the present invention. This design uses gears that do not switch between the gear set of a larger moment of force and that of a smaller moment of force during the combustion expansion portion of the cycle. However, the gears used in the engine could not be easily produced.
There are other cat and mouse type rotary engine designs which do not use gears, such as that of Japanese Patent Application Hei 04-212339. This design utilizes a dynamo-electric mechanism to gain rotational motion. However, use of a dynamo makes for a complicated, large, and heavy device, with the attendant reduced efficiency of power conversion.
The cat and mouse type rotary engine of this invention includes a groove arranged on a side of each rotor. Over the course of a full rotation of the rotor, the distance between a point along the groove and an axis of rotation of the rotor changes. The groove may include arc and line sections whose tangential line is different from that of other parts of the groove relative to rotational direction. The groove moves a small bar that fits into the groove in a manner that the bar can freely slide along the groove. A component of a force toward a rotational movement provided to the bar is larger than that of another bar, which rides in another groove. The larger force is drawn to a gear which may be a planetary gear that is held by a rod so that the rod, firmly attached to an output shaft, rotates the output shaft in the intended direction.
The present invention has as its object a practical cat and mouse type rotary engine, a cat and mouse type rotary engine with fluid compressor/blower, and a cat and mouse type rotary fluid compressor/blower driven an external power source, to run: 1) without damage or heavy abrasion to any parts; 2) with efficient and unstrained conversion of power; 3) by using parts that may be produced without undue difficulty; 4) utilizing a simple and small structure; and 5) without unusual manufacturing requirements, with a resulting low process cost and high productivity.
These objects are achieved through the present design for a cat and mouse type device including: a housing; a shaft rotatably mounted within the housing; first and second rotors rotatably mounted within the housing, each of the rotors having at least two rotorheads arranged around a perimeter of the rotor, the rotors being mounted within the housing to define an annular volume, with the rotorheads dividing the annular volume into a plurality of chambers, each of the rotors having a groove disposed on a face of the rotor; at least one rod secured to the shaft within the housing; at least one primary gear rotatably mounted to each of the at least one rod; at least one secondary gear mounted within the housing and surrounding the shaft; a plurality of bars extending away from the at least one primary gear; at least one inlet passage and at least one outlet passage in the housing, each said inlet and outlet passage opening into the annular volume; wherein each of the bars is arranged to ride in one of the rotor grooves and each of the at least one primary gear is meshed with the secondary gear.
It is another object of the present invention to provide a cat and mouse type device which is configured to prevent improper rotation of the rotors due to unintended movement of the bars. This is achieved by further including in the cat and mouse engine primary gear protuberances extending away from each said primary gear, and rotor protuberances extending away from each said rotor. The primary gear protuberances are arranged to interact with the rotor protuberances to prevent the rotors from deadlocking during operation.